Mercury switch



March 7, 1933. SNAVELY 1,900,080

' MERCURY SWITCH Original Filed April 16, 1929 2 Sheets-Sheet l M 23 16 fi Z 1a;

,4. J2 5 3 1: I29 14 J f- March 7, 1933. E s v 1,900,080

MERQURY SWITCH Original Filed April 10, 1929 2 Sheets-Sheet 2 3nvcntor ZZZ Jfiavelg/ (Ittorneg Patented Mar. 7, 1933 "UNITED STATES PATENT OFFICE- EARL EUssELL SNAVELY, or EosELLE, NEW JERSEY, ASSIGNOR 'ro THE EmE ma co., me, or UNION, NEW JERSEY MERCURY SWITCH Application filed. April 10, 1929, vSerial This invention relates to electrical circuit makers and breakers and has special reference to a mercury switch.

Among the important objects of the invention is the provision of an improved mercury switch wherein contacts are made and broken through gyratory movement of a contact carrying mercury holding trough or annular channel; the provision of a novel baflle or 19 partition arrangement for eliminating vaporization of the mercury through localized sparking; and the novel arrangement of certain of the contacts in separate cells or pockets whereby a series of circuits may be closed and broken one after the other. 7

lVith the above and other objects in view certain embodiments of the invention will now be described in detail and the invention will be particularly pointed out in the appended claims, reference beingv had to the accompanying drawings, wherein 2- Figure 1 is a vertical diametric section of a mercury switch constructed in accordance with this invention.

Figure 2 is a perspective view partly broken away, of the body of the switch.

Figure 3 is a detail showing a portion of the universal joint used to permit gyratory motion of the body.

Figure 4 is a slightly enlarged detail section on the line cc of Figure 1.

Figure 5 is a section through the peripheral trough or channel portion of the body to show the cell,-partition and contact arrangement used herewith.

Figure 6 is a diagrammatic section showing a modified form of switch body.

. Figure 7 is a diagrammatic plan of the modified form.

Referring to the form shown in Figures 1 to 5 incluslve, a base 10 is provided with spaced standards 11 projecting upwardly therefrom. Arms 12 project toward each other from the tops of these standards and ends of these arms. A shaft 14 has its ends journalled in these sockets and passes through an opening 15 formed in a stem or stub 16. A pin 17 passes through the opening 15 from side to side of the stem 16 and the shaft 14 alined sockets 13 are-formed in the proximal No. 354,159. Renewed July 20, 1932.

The switch body has a central portion con- I sisting of parallel top and bottom walls 21 and 22 respectively, the lower plate having the upper end of the stem 16 fixed centrally of its under side and projecting downwardly at right angles therefrom. The upper plate 21 overhangs the lower plate at its peripheral portion, being concentric to and of greater diameter than this lower plate. Frusto-coni- 'cal walls 23 extend downwardly from the peripheries of the plates 21 and 22 parallel to each other and a bottom 24 closes the space between the free edges of the walls 23 thus forming, with these walls, an annular trough or channel. The angular relation between the walls 23 and plates 21 and 22 is such that the portions of the walls 23 which are in their lowermost position will always be perpendicular. This switch body is formed throughout all of its walls of .suitable insulating material such as glass, bakelite or the like. An annularpartition 25 extends upwardly from the bottom 24 to about one-half the depth of the channel and is spaced somewhat nearer to the outer wall 23 than to the inner wall 23.

QRadial walls 26 extend inwardly from the partition to the inner wall 23 and divide the space between the partition 25 and inner wall into a series of cells. These walls 26 have their upper edges inclined so that murcury M held in the lower portion of the trough will, as the switch body gyrates, flow over the wall between an inactive cell an an active or full cell along the whole crest or top edge of the wall. An annular cover plate 27 projects out from the inner wall 23 over the top of the walls 26 adjacent said inner wall so that as each cell rises to the position shown at the left of Figure 1 a certain amount of the mercury M will be retained in the cell.

A terminal 28 is suitably fixed in the botti tom of each of the cells formed between the walls 26 and a flexible conductor 29 leads from each terminal 28 to a respective binding post 30 mounted on the base 10. These binding posts are intended to enable connection to be made through suitable conductors to a plurality of translating devices which it is desired to actuate in succession. An annular'terminal 31 extends completely around the channel between the partition 25 and outer wall 23 and a flexible conductor 32 connects this annular terminal to a binding post 33.

In the form of the invention shown in Figures 6 and 7 the body of the switch forms an annular torus and is made from a tube 34. Spaced cells 35 depend from the under part of this tube. An annular terminal 36 extends within the tube 34 and in each cell is a terminal 37 In this form the mounting and connections will be, although not here shown, of the same nature as previously described.

In operation the gyratory movement of the multi-switch body causes the mercury, which is mainly held in the lower portion, to flow over the walls 26 in succession. If

desired there may be sufficient mercury to fill several cells on the lower side. A portion of the mercury is retained in the respective cells by the cover plates 27. As each cell approaches the lowest position it dips into the pool of mercury which then flows over the crest of the wall 26 along its entire length simultaneously. The circuit is thus closed successively between the plate electrodes 28 and the annular ring terminal 31. The inclination of the crest or upper edge of the walls 26 is at such an angle that the mercury in the cell separates from the pool of mercury simultaneously along the entire length of the crest of the wall, thereby distributing the spark at the break over such a considerable cross section of mercury so that there will be no undue heating, thus practically eliminating any vaporization of the mercury. I

It will be noted that the body of the switch is filled with some inert gas so that any slight vaporization of mercury which may take place will not result in a chemical compound being formed between the mercury and the gas in the body.

I claim:

1. In a mercury switch, a body having an annular channel adjacent its periphery and containing mercury, a partition in said channel between its walls and extending upwardly from the bottom of the channel, radial walls extending from the partition to the inner wall and dividing the inner part of the channel into cells, an electrode in each c ll,

eoaoeo cell, an electrode extending around the chan- 4.

nel between the partition and the outer wall, means to support the body for gyratory movement, and a cover plate resting on the inner parts of the radial walls and covering the inner portions of the cells.

3. In a mercury switch, a body having an annular channel adjacent its periphery and containing mercury, a partition in said channel between its walls and extending upwardly from the bottom of the channel, radial walls extending from the partition to the inner wall and dividing the inner part of the channel into cells, an electrode in each cell, an electrode extending around the channel between the partition and the outer wall, and means to support the body for gyrator movement, the top edges of the radial wal s being inclined upwardly from their inner to their outer ends to cause overflow of mercury to take place along the entire top edge of each respective wall in succession as the body is gyrated.

In a mercury switch, a body having an annular channel adjacent its periphery and containing mercury, a partition in said channel between its walls and extending up from the bottom of the channel, radial walls extending from the partition to the inner wall and dividing the inner part of the channel into cells, an electrode in each cell, an electrode extending around the channel between the partition and the outer wall, means to support the body for gyratory movement, the top edges of the radial walls being inclined upwardly from their inner to their outer ends to cause overflow of mercury to take place along the entire top edge of each respective wall in succession as the body is gyrated, and a cover plate resting on the inner parts of the radial walls and covering the inner portions of the cells. I

5. In a mercury switch, a body mounted to permit gyratory movement about a vertical pivot, said body having a sealed chamber comprising an annular chamber, an annular partition dividing said chamber into two concentric compartments, an annular electrode in one compartment, a plurality of electrodes in the other compartment spaced apart, a

est position, and means to impart a gyratory movement to said switch body about a vertical plvot. v

6. In a mercury switch, a body mounted 6 to permit gyratory movement, said body having a sealed chamber provided with an annular channel having depending frusto-conical walls, an. annular partition between said walls extending upwardly from the bottom 1 of said chamber, radial walls extending from the partition to the inner wall and dividing the inner part of the channel into cells, an

electrode in each cell, an electrode extending around the channel between the partition 5 and the outer wall, a quantity of mercury in said channel sufiicient to flow over said walls" as the cells are moved into the lowest position during the gyratory movement of the switch body and means to'impart a gyratory movement to said body about a vertical pivot.

' EARL RUSSELL SNAVELY, 

